In a leaf spring assembly used in a suspension for vehicles (cars or the like), plural leaf springs are laminated, and a U-shaped bolt, which holds the leaf springs, is mounted from an upper side of a longitudinal direction central portion to the leaf springs. In this case, for example, a spacer is provided between the leaf springs at the longitudinal direction central portion, and for example, a pad is provided between the uppermost leaf spring and the U-shaped bolt. In the leaf spring assembly, both end portions of the U-shaped bolt are fastened to an axle disposed at a lower side of the lowermost leaf spring.
In this leaf spring assembly, a silencer is provided between the leaf springs at both longitudinal direction end portions thereof. The silencer is used to prevent generation of undesirable noises by sliding of the leaf springs. In the silencer, a projection portion is formed at one surface facing the leaf springs, and the projection portion is fixed at a hole of the leaf spring. Thus, the silencer is fixed at the leaf spring (fixing side leaf spring).
In this silencer, the following characteristics are required. That is, since the projection portion receives shearing force from the fixing side leaf spring, it is necessary that the projection portion have sufficient strength. Since another surface (surface opposite to the one surface having the projection portion formed thereat) of the silencer slides on the leaf spring (sliding side leaf spring), at the another surface of the silencer, wear resistance is required, and prevention of undesirable noises generated by sliding on the leaf spring is required.
In consideration of these circumstances, in order to improve strength of projection portion, a technique has been proposed in which a reinforcing hardware is provided inside a silencer made of a rubber compact (see Patent Document 1, for example). On the other hand, in order to prevent undesirable noise generation, a technique has been proposed in which two silencers, which are made of the same material, are laminated between leaf springs and slide on each other (see Patent Document 2, for example).
Patent Document 1 is Japanese Unexamined Patent Application Publication No. 2007-247754. Patent Document 2 is Japanese Unexamined Utility Model (Registration) Application Publication No. H6-65634.